7751-67-9Relevant academic research and scientific papers
Synthesis of 3&β,29-Dihydroxystigmasta-5,24(28)(E)-dien-7-one
Le, Phu H.,Preus, Martin Wuu,McMorris, Trevor C.
, p. 2163 - 2167 (1982)
The synthesis of 3β,29-dihydroxystigmasta-5,24(28)(E)-dien-7-one from 3β-acetoxy-22,23-dinorcholenaldehyde has been achieved in an overall yield of 7 percent..Witting reaction of the aldehyde and diethyl (3-methyl-2-oxobutyl)phosphonate anion gave 3β-acetoxycholesta-5,22-dien-24-one which was hydrogenated selectively, and the saturated ketone was allowed to react with the anion of diethyl (cyanomethyl)phosphonate.The resulting nitrile was reduced via the alehyde to 29-hydroxyfucosterol by using DIBAL-H.Acetylation of this diol and oxidation with chromium trioxide-3,5-dimethylpyrazole afforded the 7-ketone.Mild hydrolysis of the acetate groups completed the synthesis.
Silver-Catalyzed Oxidative C(sp3)?P Bond Formation through C?C and P?H Bond Cleavage
Li, Lili,Huang, Wenbin,Chen, Lijin,Dong, Jiaxing,Ma, Xuebing,Peng, Yungui
supporting information, p. 10539 - 10544 (2017/08/22)
The silver-catalyzed oxidative C(sp3)?H/P?H cross-coupling of 1,3-dicarbonyl compounds with H-phosphonates, followed by a chemo- and regioselective C(sp3)?C(CO) bond-cleavage step, provided heavily functionalized β-ketophosphonates. This novel method based on a readily available reaction system exhibits wide scope, high functional-group tolerance, and exclusive selectivity.
Stereoselective synthesis of 24-hydroxylated compounds useful for the preparation of aminosterols, vitamin D analogs, and other compounds
-
Page/Page column 28, (2016/11/02)
A method is described for stereoselectively reducing an unsaturated alkyl ketone substituent attached to a fused ring base. In this method, the unsaturated alkyl ketone reacts with a chiral oxazaborolidine reagent. This reaction stereoselectively reduces
One pot synthesis of mono- and spirocyclic α-phosphonato-α,β- unsaturated cycloenones
Gil, Jun Mo,Hah, Jung Hwan,Park, Kwang Young,Oh, Dong Young
, p. 3205 - 3208 (2007/10/03)
A one pot ozonolysis/intramolecular aldol condensation(with the aid of T(s)OH and Et3N as catalysts) of β-keto-ω-alkenylphosphonates provided the α-phosphonato-α,β-unsaturated cycloenone with good yields.
Preparation of 1-aminoalkylphosphonic acids and 2-aminoalkylphosphonic acids by reductive amination of oxoalkylphosphonates
Ryglowski, Artur,Kafarski, Pawel
, p. 10685 - 10692 (2007/10/03)
By reacting dialkyl 1-oxo- or 2-oxoalkylphosphonates with benzhydrylamine followed by reduction with triacetoxyborohydride and acid hydrolysis gave corresponding aminoalkylphosphonic acids with satisfactory yields. The use of benzylamine, α-methylbenzylamine and tritylamine was unsuccessful in the case of dialkyl 1-oxoalkylphosphonates whereas conversion of 2-oxoalkylphosphonates was also achieved although with lower yields.
Reaction of 2-Chlorooxiranes with Phosphites and Phosphanes: A New Route to β-Carbonylphosphonic Esters and -phosphonium Salts
Herzig, Christian,Gasteiger, Johann
, p. 601 - 614 (2007/10/02)
Reaction of alkylsubstituted 2-chlorooxiranes 6 with trialkyl phosphites 11 gives β-carbonylphosphonic diesters (12a, b, 15a, b, 20a, 21a), free of isomeric enol phosphates or α,β-epoxyphosphonates. 2-Chloro-2-(chloromethyl)oxirane (6c) undergoes with 11 an Arbusov reaction followed by a Perkow reaction ( -> 18 -> 17).The limitation of the method is probed with sterically crowded substituents in 3-position of 6. 6b yields with triphenylphosphane a β-ketophosphonium salt (23), which can be converted to a keto-ylide (24).
PHOSPHOR- UND SCHWEFELSUBSTITUIERTE ALLENE IN DER SYNTHESE I : EINFACHE SYNTHESE VON β-KETOPHOSPHONATEN AUS 1-ALKIN-3-OLEN
Altenbach, Hans-Josef,Korff, Rainer
, p. 5175 - 5178 (2007/10/02)
Allenic phosphonates, readily accessible from 1-alkin-3-ols, the addition products of 1-alkines to aldehydes or ketones, can be transformed to β-ketophosphonates by nucleophilic addition of diethylamine and subsequent hydrolysis of the formed enamines.
β-Ketophosphonsaeureester aus α-chloroxiranen
Gasteiger, Johann,Herzig, Christian
, p. 2687 - 2688 (2007/10/02)
β-Ketophosphonic ester can be obtained by the treatment of α-chloroepoxides with trialkylphosphites.
